Installation for welding or casting under molten slag cooled closure plates



Feb. 23, 1965 M. 315% 3,170,430

FOR WELDING CASTING UNDER INSTALLATION MOLTEN SLAG COOLED CL RE PLATES Filed Jan. 24. 1962 2 Sheets-Sheet 1 INYEIg TPR. )fifcha/ 50*0/6 BY Feb. 23, 1965 M. BISTAK 3,170,430 INSTALLATION FOR WELDING OR CASTING UNDER MOLTEN SLAG COOLED CLOSURE PLATES Filed Jan. 24, 1962 2 Sheets-Sheet 2 WM &/

- not suited for any type Of'WEld.

United States Patent Ofiice 3,17 430 I INSTALLATION FOR WELDING 0R CASTING pULNADTlglg MOLTEN SLAG COOLED CLOSURE Michal Bistak, Bratislava, Czechoslovakia, assignor to Yyskumny listav zvaracskyMHD Bratislava, Czechoslovakia I v v Filed Jan. 24, 1962, Ser. No. 168,377

Claims priority, application Czechoslovakia, Feb. 3, 1961, PV 617/61 9 Claims. (Cl. 113,-136) The present invention relates to improvements in a mechanism for pressing' intoo'perative engagement cooled closure plates of a device forfautornatic welding or casting under molten slag, so-called under-slagewelding. H v The'process of welding or casting under molten slag is characterized by the containmentof the entire welding bath, in a metallic mold formed by the walls of the workpieces tobe welded and by two cooledflclosure plates.

Such plates form either part of-= the welding'or casting installation and are referred to asuniversal closure plates in that they are applicable to work-piecesof different shapes, or are provided as specialcl'osure plates of varying length and shape, which are pressed against the "welded work-pieces independently of the weldin'g devicem work-pieces, which shortcoming considerably complicates and hinders the handling of the cooled closure plates during preparation of the welding installation for the weldingfprocess.

The principal objectofthe present invention is to avoid the aforementioned disadvantagesby providing a universal pressure mechanism which can be used-in con- 'nection with cooled closure plates of any design, andwhich is suitable for the production of straight'and circumferential welds, while permitting exact "guiding of the cooledsclosure plates, particularly in the direction transverseto the weld.- I 1 I s The universal pressure applying mechanism according to the invention comprises substantially-as in heretofore known devices of this type-two pressure exerting 7 devices each urging a cooled closure plate against a side of the welding gap,- the two sides being opposite each other.-;- The pressure or force is transmitted through pres sure applying rails to .thecooledelos'ure plates iAccording to the main feature of the invention, the pressure rails are slidably mounted 'onone of}; two-armed Iever,- '\'vhic h isjournalledon apivot-earriedi by an actuating arm. "Ihe'other arm or part of the twoarmed lever is connected 'to the actuating arm' by means Whether welding with stripelectrodes or with wire elee- I I trodes, universal cooled closure-plates are, mostly used.

The wayin which the closure plates are pressed into 'operative'engagement with the work-pieces is of particular importance and affects not only the safetyandt "dependability of the entire welding installation but also the shape and quality of the weld surface.

The cooled closure plates have heretofore been pressed against the treated work-pieces by means of mechanisms which ,do not permit adjustrnentjof the *positionof the cooled closureplates when the welded pieces are otfset "or inclined with-respect toone another.

The known mechanisms do not permit vertical adjustment Qf'fthe point of application of the' pressure force neither during of a set screw for'adjusting the position atwhich rounded, outer edges of the pressure rails are contacted by a; beam pivotally mounted in the actuating arm and transmitting the'pressureor' force to'the rails. According to a vfurthe r, feature of the inventiom the front or inner ends of the rails are preferably provided with exchangeable end-pieces having 'arcuate facesbearing directly'on the cooled closure plates so that the aXispassingthrough of the arcuatefaces the'center of the radius of curvature lies in 'a'horizontal p'lane.

so In the case of the pressure applying device in front of the welding gap, the actuating arm is clamped 1 in a sleeve slidable on a' guide bush containing a known 7 spring mechanism {for exerting the desired force generally in the desired direction of thelatter.

engagement with the work-pieces resides in the fact that their mountingon the welding installation does-not allow, the maintenance of the alignment of thewelding gap with. the'cooled closure plate during the welding process since the cooled closure plates cannot be shifted in-the hori- ,'zontal direction transversely; of the weld. tMechanisms I for pressing the closure plates into operative engagement 1 'withthe work-pieces by a parallelogramor simply" by a U-shaped element are objectionable in that tit-he work piecesto be welded are offset, the spacing "between the sides of theparallelog'ram changes during the. welding operation, which factnec'essitates wider guiding channels tobefprovided in the cooled closure plates. vConsequently, the cooled closurejplates can deviate from the quality of the'weld and caneven'result'inan interrup;

tion of the welding operation. Moreover, in the here toforefproduced welding installations the'mechanis'ms for pressing the cooled closure plates into operative engage? 'rn'ent with thework-pieces afe' rigidly mounted-and can tgieret dre, not "be shifted, toward audaway m the In the case of the pressure applyingdevice inbaclr of the welding gap, the actuating arm also forms the horizontal link of a vertical'parallelogram, which further comprises vertical'links and asuspension member. The spring mechanism exerts the" force generally 'atrightjangles to the desired direction against a bell-crank pivoted' onl the suspension member and acting against'the horizontal link formed bythe actuating arm. This mechanism is, according to a further feature of the invention, preferably suspendedfrorn a-knifewhich is displaceable in a hoi'izontal and vertical plane and extendingacross the welding gap Further features andradvantages of the present invention-will appear in the following detailed-description-of an illustrative embodiment which is to be read in connec tionwith the accompanying drawings, wherein:

, :5, FIGURE 1 is a perspectiverview of aweldinginstalla' i tion provided a mechanism for pressing the cooled closure; "plates. against the work-pieces at the sides ofithe welding gap in accordance with this invention,

longitudinal sectional view of FIGURE 2 is} part of the pressure mechanism 'and 'i'FIGURE 3 is a longitudinalsectionaljview-g gum irearpartthereof; i i

Q V iportioniot Lthepressure 1 1 axis r the welding" gap, which-innfav r b y" t a in FIGURE}, comprises two parallelpressure raila ;28, slidably mounted in dovetail slots atthe opposite sides I, r of aitwo-arrned lever 26, to transmit the force of: the spring :15 to a cooled front closure-plate 33, saidpre'ssum';

railsgzttare equippedwith exchangeable end-piecesjfl, enablingtheipressure mechanism to be used in 'COIIHOCe tion with cooled closure plates oi various designs. 7

force acting on both pressurerailsl l} -is transmitted to Patented Feb. 23, 1965 relative. to one another.

the latter by means of a beam 27 pivotally mounted, at

its center, on a vertical pin carried by an actuating arm 25. Since rails 28 are slidably arranged in the dovetail portions of lever 26 and the pressure force is transmitted to the rails 28 by means of the beam 27, the pressure forcetcan urge both sections of the cooled closure-plate tightly against the work-pieces even if they are offset The spacing between pressure rails 23 does not change, so that exact guidingfof the cooled'closure-plate 33 can be achieved.

The lever 26 is pivoted onv the arm 25 by means of a horizontal pin 22. The two-armed lever 26, along with the pressure rails 23, can be angularly displaced relative F to arm 25 about the pin 29 by means of the manually controlled set screw 32. Such angular displacementof the lever 26 and thus of pressure rails 23 serves to'vertically displace the point of application of the pressure force upon the cooled closure plate 33. This displace-'1 ment is further assisted by the exchangeable-end pieces of the pressure rails 28 which are provided with a 1 slightcu-rvature, as shown on FIG. 2 in 'brokenlines. I

The screw 32 is mounted in a cylindrical nut 31 turnable about an axis parallel to pin 29' in the ,lever 26 and'is'secured in the arm 25 againstmovementdn axial direction, but is ,free to rotate in a bushing 24 which is turnable inan arm 25 about anaxis parallel to pivot pin 29. By turning the sjcrewi32 in one direction, the cylindrical nut -31 moves downwardly along the screw 32 and lever 26 turns about-the pin 29 in the clockwise direction. The vpoint of application of the pressure ,torce H .bylthepressure rails 2S to closure plate 33is displaced downwardly below the center of the cooled closure plate 33. By turningthe set screw 32in the oppositedirection,

"center-ofthe coolecljclosureplate 33.

In this ,way the pressure force acting on-the cooled closure-plate 33 can easilyrbe concentrated at points where itis most necessary for maintaining contact of the nut 31' moves upwardly along screw '32 so that lever A 26 rocks,=, along with pressure rails 28, about the, pin 29 inthecountercloclcwise direction and the point of application of the'pressure force is shifted above the plate with the welded work-pieces. However, the most 1 important advantage of. the described mechanism is that itcan' be used without any adaptation whatsoever even for the production of circumferential welds, as the set screw 32 ,enables'the cooled closure plate 33 tobe adjusted to any radius of cylindrical i'work-piece's which are a to,be welded.

The pressuremechanism according to the invention permits easy manipulation not only during the prepare tion.;of the installation for the welding process, but also after the welding process has been terminated, due to .the special mounting of the pressure mechanism onthe fwelding installation. 7 I

-Thearm 25 of thepressure mechanism terminates in a collarip'rovided with a circumferential groove of arcuate even in'the course of the welding process. Secured to s cross-section, and inserted into the clamping sleeve 20.

The VcIampingr sleeve 20' is tightened on the collar by means of a screw 19, which partiallyengages the groove of .arcuateecross-section provided in the collar of the arm 25,; The ann25 can, thus, be adjusted as awhole about justed-by-means of -a slidable 'nut'14 movable axially along a screw 13 which carries a handwheel. The-spring mechanism is actuated by turningthe handwheel, wherey by the clamping sleeve 20 along with the arm 25 is urged away from or towardthebush 18-, with-the resultfthat the cooled closure plate 33 is pressed against the welded work-pieces or removed from them.

- In order to arrange for lateral manipulation of the front portion of the pressnre'mechanism, that is, the manipulation transversely of the weld, use is made of the mechanism within a sleeve 21 which forms a pant of a cross-holder. Lateral movements of the front portion are controlled by a hand. wheel 23 with the aid of a screw and a nut" (not shown) provided within the sleeve 21 and by sliding the sleeve 21 along a tubularsupport 22. The mechanism used for lateral adjustments is similar to that used for movements of the pressure mechanism toward and from the work-pieces. As for the latter'mechan-ism, thebush 18,.the clamping sleeve 26, the; arm 25, and associated parts are actuated to shift the front portion of the pressure mechanism toward and away from the work-pieces, whereby the bush 18 slides within the sleeve 17, another part 1 of the referred to cross-holder, The sleeve 17 is secured to the sleeve 21 to form together with thelatter'an integral pant. Once the cooled closure plate 33 has been roughly adjusted relative to the work-pieces to-be welded, the pressure mechanism is fixed by clamping the guide bush 18 in the sleeve 17 by means of a screw with at handleijlo. j The appr'opriatepressure force is then obtained by adjustingthe compression of the spring 15.

, This-is accomplished by turningthe handwheel and thereby "also the pressure screw13 in counter-clockwise direc- 'tion.

I The pressure mechanism including the cooled closure plate33 can be displaced horizontally in the transverse direction with respect to the weld not only during adjustrnent,ot the pressure mechanism prior to, but alsoin'the, "courseof :the Welding operation. This is eifeoted, as has' already been indicated, by shifting the lower sleeve 21 of the cross-holder along a tubular support 22 byirotation of a hand-wheel 23. -The tubular support 22 is rigidly "fixed to awslide provided on the welding installation so that theentire pressure mechanism travels during: the

welding operation in vertical direction of welding with the speed of movement of said slide.

The back portion of the pressure mechanism, which is shown: in detail in FIG. 3, comprises a suspension member 4Fdepending from a knife 36 extending preferably through the welding gap and fixed to alongitudinal support provided on the welding installation and adjustable in the horizontal and vertical plane. If the longitudinal suppont of the installation is secured to a transverse support, the-knife 36 together with the suspension memberx i and the entirerear pressure mechanism can "be adjusted by hand transverseiy tothe weld, as desired,

the suspension actuated mechanism'l is a spring member of knowndesign comprising a spring I mounted within a sleeve threaded, in a lug of member 4 so as'to be vertically adjustable, Thespring 1 acts downwardly on a headed pin3 which engages abell-crank 5 pivoted on suspension member 4. The downwardly directed arm of bell-crank 5- carries, a pin'engaging in agroove formed at the center of across-head formed'at Ithe'upper end of the actuating '7. The cross-head at the top of' arm 7 is suspended pivotally from theilower endofmember 4 bytwojyertical links 6.- It will be apparent that links 6 and the portions of member 4 and of. arm 7 connected -thereby, form a deformable parallelogram. I A=;lever 8' is pivoted about a horizontalpin 9 on the arm 7, and .hasdove-tailedportions in which the pressure rails 35-are slidably mounted. f ,The pressure rails 35 carry exchangeable end-pieces5137 which are designed in the -same way as the pressurerails 28 of the 'frontportionshown inFIG. The pressure force is transmitted to the pressure rails 35 by means of a s ,a beam lti s wingable about a vertical pivotcarried by. arm'j. In addition to the; connection thronghsthe pin 9,,

j the arm 7and thelever Sareconnected by a setscrew 12} provided 'wnhja right-hand and left-hand threaded a d The rear pressure-mechanism operates as follows: By

increasing the pressure of the spring 1 in the spring member, the arm 7 and the lever 8 are shifted horizontally through the bell-crank 5, with the result that the cooled closure plate 34 is pressed, \m'th the aid of pressure rails 35, against'the work-pieces undergoing welding. Due to the fact that the force acting on the pressure rails 35 is transmitted thereto by means of the beam and that the pressure rails 35 are slidable in the dovetails of the lever 8, the pressure force is distributed uniformly between both pressure rails 35 even when the work-pieces are offset relative to one another.

The point of application of the pressure force can be displaced in the vertical direction by means of the set screw 12. As one part of the screw is provided with a left-hand and the other with a right-hand thread, rotation of the screw causes rocking movement of the lever 8 and rails 35 about the pin 9 relative to arm 7. By reason of the slightly curved end-pieces 37 of rails 35 which contact the cooled closure plate 34, the points of contact with the latter are moved upwardly or downwardly by such rocking of the rails 35.

The universal pressur mechanism according to the invention represents a considerable advance in the art, as it permits extensive adjustment of the welding installation before and during the welding operation, and above all rapid setting-up of the installation preparatory to the welding process, as well as quick re-adjustment, if and when required, even while the welding operation is under way. This is feasible mainly due to the whole pressure mechanism being slidable over a relatively large distance in the horizontal direction perpendicularly to the treated work-piece, which is of particularly importance when the welding process has to be interrupted and the liquidslag speedily discharged.

The pressure mechanism according to the invention affords the further advantage of being capable of use in connection with the production of straight and circumferential welds by reason of the possible vertical displacement of the point of application of the pressure force along the cooled closure plate. The pressure mechanism and back of the work-pieces for containingthe molten slag in the gap; front and back pressure applying devices for holding the closure plates tightly against theworkpieces, each of said devices comprising an actuating arm, means mounting said arm for generally horizontal movement toward and away from the work-pieces, a horizontal pivot on said arm, a lever swingable on said pivot relative to said arm, pressure exerting rails slidably mounted on said lever for generally horizontal movement relative to the latter, said rails having arcuate surfaces at one end for bearing against the related closure plates, a

beam pivoted on said .arm to swing relative to the latter about a vertical axisand bearing against the other ends of said rails, means for exerting a force urging said arm toward the work-pieces, whereby said beam uniformly transmits said force to said rails for application by the latter to the related closure plates, and adjustable screw means 7 connected to said arm and lever for angularly displacing according to the invention can be used for cooled closure plates of any desired design, consisting either of one, two or three parts. The accuracy with which the closure plate is guided, particularly transversely to the weld, is superior to that which can be achieved with the heretofore known pressure mechanisms; this is due to the replacement of the horizontal parallelogram of the known devices by the dovetail mounting of the pressure rails, so that the spacing between the latter does not very during operation. The design of the rear portion (FIG. 3) of the pressure mechanism embodying the invention is such that this portion occupies the smallest possible space .to avoid the use of large yokes for clamping the work-pieces under treatment.

The advance in the art achieved by the pressure mechanism according to the invention is to be seen in its safety of operation, its advantageous design in comparison with heretofore known mechanisms, which results in quicker and easier servicing, its all-round-usabilitynot only with regard to the treated materials but also thecooled closure the latter and said rails relative to said arm about said horizontal pivot, thereby to vertically vary the locations of the contacts of said arcuate surfaces of the rails with the related closure plates.

2. In an apparatus for welding under molten slag, front and back pressure applying devices as in claim 1; wherein said arcuate surfaces at one end of the pressure rails are substantially concentric with the axis of said horizon tal pivot, and said other ends of the rails engaged by said beam are also arcuately concentric with said horizontal pivot.

3. In an apparatus for welding under molten slag, front and back pressure applying devices as in claim 2; wherein said arcuate surfaces at said one end of the rails are formed on replaceable end pieces.

4. In an apparatus for welding under molten slag, front and back pressure applying devices as in claim 1; wherein said means mounting the arm of the front device includes a horizontally extending sleeve clamped on said arm and a guide bush onto which said sleve is axially slidable; and wherein said means for exerting a force on said arm includes a spring actuated mechanism mounted in said guide bush and acting against said arm.

5. In an apparatus for welding under molten slag, front and back pressure applying devices as in claim 4; wherein said arm of the front device has a collar extending into said sleeve and formed with acircumferential groove, and said clamping sleeve is releasably secured on said collar by means of a tangential clamping screw engaging in said groove to prevent axial displacement of said collar relative to said sleeve.

6. In an apparatus for welding under molten slag, front and back pressure applying devices as in claim 1; wherein said adjustable screw means of each of the devices includes a screw member, and bearing members engaged by said screw member and being turnable in said arm and said lever, respectively, about axes parallel to said'horizontal pivot.

7. In an apparatusfor welding under molten slag, front and back pressure applying devices as in claim 6; wherein said screw member of the front device is threadably engaged with the related bearing member in said lever and held against axial displacement relative to the bearing member in said arm. I

8. In an apparatus for welding under molten slag, front and back pressure applying devices as in claim 6; wherein said screw member of the back device has portions thereof with left and right-hand threads, respectively,

which are threadably engaged with said bearing members member and pivotally connected to said arm 'so that the latter is movable toward and away from the work-pieces upon swinging of said links; and wherein said means for exerting a force urging said arm of the back device toward the Work-pieces includes a bell-crank pivoted on said suspension member and having a generally vertical leg and a generally horizontal leg, coupling means between said vertical leg and said arm, and spring actuated means mounted on said suspension member alongside the latter and bearing against said horizontal leg of the bell-crank to urge the latter to rock in the direction moving said arm toward the Work-pieces.

References Cited by the Examiner UNITED STATES PATENTS 986,619 3/11 Bach 269l39 XR Zawadzki 269-203 Skinner l1399 Clarke 269-256 XR Rockefeller 219-126 XR La-Placa 269139 XR Ballentine et al 2l9-l26 Hess Q 21973 Lucas 219-126 Schultz 269-60 Wooding et al. 113-l36 CHARLES W. LANHAM, Primary Examiner.

JOHN F. CAMPBELL, ROBERT F. WHITE, Examiners. 

1. IN AN APPARATUS FOR WELDING UNDER MOLTEN SLAT IN A VERTICAL WELDING GAP BETWEEN WORK-PIECES AND HAVING COOLED CLOSURE PLATES EXTENDING ACROSS THE GAP AT THE FRONT AND BACK OF THE WORK-PIECES FOR CONTAINING THE MOLTEN SLAG IN THE GAP; FRONT AND BACK PRESSURE APPLYING DEVICES FOR HOLDING THE CLOSURE PLATES TIGHTLY AGAINST THE WORKPIECES, EACH OF SAID DEVICES COMPRISING AN ACTUATING ARM, MEANS MOUNTING SAID ARM FOR GENERALLY HORIZONTAL MOVEMENT TOWARD AND AWAY FROM THE WORK-PIECES, A HORIZONTAL PIVOT ON SAID ARM, A LEVER SWINGABLE ON SAID PIVOT RELATIVE TO SAID ARM, PRESSURE EXERTING ON SAID PIVOT MOUNTED ON SAID LEVER FOR GENERALLY HORIZONTAL MOVEMENT RELATIVE TO THE LATTER, SAID RAILS HAVING ARCUATE SURFACES AT ONE END FOR BEARING AGAINST THE RELATED CLOSURE PLATES, A BEAM PIVOTED ON SAID ARM TO SWING RELATIVE TO THE LATTER ABOUT A VERTICAL AXIS AND BEARING AGAINST THE OTHER ENDS OF SAID RAILS, MEANS FOR EXERTING A FORCE URGING SAID ARM TOWARD THE WORK-PIECES WHEREBY SAID BEAM UNIFORMLY TRANSMITS AND FORCE TO SAID RAILS FOR APPLICATION BY THE LATTER TO THE RELATED CLOSURE PLATES, AND ADJUSTABLE SCREW MEANS 